[Objective] Soil conservation plays an important role in preventing soil erosion. We choose Qinghai Lake basin as the research area to examine and assess the temporal-spatial variation pattern of soil conservation quantity. [Methods] Universal soil loss equation(USLE) and GIS technology were used to illustrate the variation of soil conservation quantity from 1987 to 2010. [Results] The soil conservation quantities in Qinghai Lake basin were at an average of 4.68×10⁸ t/a in the past 24 years. The high conservative areas of soil conservation capacity per unit area were at the upper and middle reaches of main river in Qinghai Lake basin, and the areas with low conservation level was around the Qinghai Lake and at the northwestern of Qinghai Lake basin. Among different regional ecosystems, the amount of soil conservation in the alpine meadow was the maximum, with an average of 2.68×10⁸ t/a. Total quantities of soil conservation in Qinghai Lake basin showed an increase-decrease trend from 1987 to 2010, and it reached the largest in 2005. Compared with the one in 1987, soil conservation quantities in Qinghai Lake basin increased to 2.17×10⁸ t by the end of 2010. The increment of soil conservation quantities in alpine meadow was the largest, about 1.2×10⁸ t. [Conclusion] In the past 24 years, soil conservation capability of Qinghai Lake basin increased and soil erosion slowed down, the ecological environment of Qinghai Lake basin got better and better.